A conventional DC motor is constructed in such a manner that bearings that support its rotor are axially biased by biasing members such as spring washers to prevent the rotor from wobbling and axially displacing (for example, refer to Patent Document 1).
Another conventional motor is constructed in such a manner that its stator and bearings are insert-molded to improve their concentricity (for example, refer to Patent Document 2).    Patent Document 1: International Patent Application Publication No. WO01/005018 (FIG. 2), and    Patent Document 2: Japanese Patent Application Publication No. 2005-218146A (paragraphs [0011] and [0005]
In the DC motor disclosed in Patent Document 1, rotor supporting bearings are held axially in position by being biased axially using, for example, biasing members such as spring washers to prevent the rotor from wobbling and axially displacing. However, in the DC motor, although the rotor is held in position with respect to the bearings by the spring washers, the bearings are not set in position with respect to the stator. In other words, since the stator and the rotor are not set in position with respect to each other, their positions become inaccurate, which has resulted in a problem causing wobble and axial displacement of the rotor.
While it is conceivable, as with the motor disclosed in Patent Document 2, that bearings are held axially in position by insert-molding the bearings and the stator, the bearings and the rotor in the motor are not axially positioned with respect to each other, which has led to a problem causing wobble and axial displacement of the rotor when an external force is axially applied to the rotor.